In the past, clutches have been designed as integral units which are mountable, essentially as a unit, on a shaft.
There are certain disadvantages to such clutch constructions. Firstly, the clutches are designed, and the working parts thereof require, that the clutch be mounted on a shaft of predetermined diameter. The designer who is to use such a clutch is therefore restricted to certain shaft diameters.
Another disadvantage is that such clutches are usually assembled on the shaft. This can cause problems in that the user of the clutch either has to assemble the clutch himself on his shaft or else have such assembly accomplished by the manufacturer of the clutch. In addition, such hand assembly is expensive.
Another problem with such clutches is field repair. When such a clutch breaks down, the entire assembly must be sent to a repair shop.
In accordance with the present invention, a modular clutch construction is provided. The modular construction includes self-contained actuating packs and self-contained reaction packs. The actuating packs include the piston structure for causing the clutch to engage. The reaction packs include the clutching discs which, when pressed together, frictionally engage each other to result in clutch engagement. These modular units can be individually demounted and mounted in the field, permitting easy replacement of a defective unit without sending the entire construction to a repair shop.
Further, the modular units include elongated hub means for mounting on a shaft. The hub means have a central opening which may be keyed or splined to a shaft. This central opening can be provided in the hubs in a variety of size ranges by the manufacturer prior to assembly of the modules. The designer or the ultimate user of the clutch is thus free to select a shaft size which uniquely suits the application in which he is interested.
A further advantage of this construction is that the output gear normally provided on the reaction pack is keyed or splined to the reaction pack as opposed to previous clutch constructions where it was welded in place. Should the gear fail in service, it is only necessary to replace the gear and not replace or repair the entire clutch construction.
In the description which follows, a double acting clutch is described. In such a construction, a reaction pack is provided on both sides of the actuating pack and the actuating pack is capable of actuating either of the reaction packs. Alternately, a single actuating pack and a single reaction pack may be incorporated into a single acting clutch which has but one output.